class DataUtil {
  factory DataUtil() => _getInstance();

  static DataUtil get instance => _getInstance();

  static DataUtil _instance;

  DataUtil._internal() {
    //内部初始化
    //init
  }

  static DataUtil _getInstance() {
    if (_instance == null) {
      _instance = new DataUtil._internal();
    }
    return _instance;
  }


  static String containerIntroduce() {
    return "Container是一个组合类容器，它本身不对应具体的RenderObject，它是DecoratedBox、ConstrainedBox、Transform、Padding、Align等组件组合的一个多功能容器，所以我们只需通过一个Container组件可以实现同时需要装饰、变换、限制的场景。";
  }

  String textUrl() {
    return "https://book.flutterchina.club/chapter3/text.html";
  }

  String buttonUrl() {
    return "https://book.flutterchina.club/chapter3/buttons.html";
  }

  String imageIconUrl() {
    return "https://blog.csdn.net/yuzhiqiang_1993/article/details/85258876";
  }

  String checkboxAndSwitchUrl() {
    return "https://blog.csdn.net/zl18603543572/article/details/94347934";
  }

  String textFiledUrl() {
    return "https://blog.csdn.net/u011272795/article/details/82528432";
  }

  String progressUrl() {
    return "https://book.flutterchina.club/chapter3/progress.html";
  }
}
